Efficient Anticancer Effect on Choroidal Melanoma Cells Induced by Tanshinone IIA Photosensitization

Tanshinone IIA (TanIIA) has multiple biological functions and already been clinically used to treat many cardiovascular diseases. TanIIA is a photoactive molecule and can be excited by light to generate ³ TanIIA*. Generation of ³ TanIIA* by TanIIA photosensitization indicates that TanIIA may serve as a photosensitizer to bring photodynamic damage to organisms. Therefore, human choroidal melanoma MUM-2B cell was chosen as a superficial tumor model and the photodynamic effect of TanIIA on tumor cells was evaluated in this study. The results showed that TanIIA photosensitization could generate singlet oxygen in noncellular system. MTT, clone formation and wound-healing assays showed that the survival and migration of MUM-2B cells could be efficiently inhibited by TanIIA photosensitization. And then, laser confocal microscope and flow cytometry were used to try to elucidate related mechanism. It was found that TanIIA could pass through cellular membrane and preferably accumulate in nucleus. TanIIA photosensitization could efficiently induce cell apoptosis and necrosis, increase intracellular ROS levels, decrease mitochondria membrane potential, and lead to cell cycle arrest in G2/M phase. Our findings indicate that TanIIA photosensitization can exert remarkable toxicity on choroidal melanoma cells.